Inverse Engineering

Project
117 Flight

Pre-flight Analysis

In this rocket, attempts were made to fix two important flaws in the 1227 rocket design. Since the engines are placed forward of the fin section, the 1227 rocket was prone to turn sharply into the wind. In this design, a 12" portion of the fin section has been removed to allow the exhaust gasses to flow over the fin section in an effort to prevent the wind from having any effect on it. This design is similar to the 622 rocket design which worked very well.
The second problem from the 1227 flight was the structural failure of the rocket casing which was made from a cardboard tube. The exhaust gasses passing through it unraveled it causing the structural failure of the entire vehicle. In this design, 30 gauge steel was used for the rocket casing. The weight of this material and the fact that the edges are so sharp, made me very uneasy about the safety of this design. Even if it works today, it will not be used again.
The engines are an untested design. I have taken what worked well on all the engine designs from 2003 and combined them to hopefully produce a K engine with a 20 second smoke tracer. Four of these engines are in the rocket and will be ignited at the same time.

Post-flight Analysis

The smoke element installed in the forward section of the engines caused an unrestricted burn in all the engines resulting in the failure of the engines. Possible solutions to this problem would be to remove any smoke generating elements from the engine design or continue experiments with the epoxy / Kno3 nozzle with a smaller diameter throat to increase the engine output.

Construction

Casing and nosecone for the rocket was made from 30 gauge steel and had several disadvantages.
Aluminum rods connected 1/2" birch ply bulkheads to hold in the engines.
Recovery was to be done with a time delay relay that closed on take-off.

Pros